If you were to look on the roof of your local city bus, what would you find? A little bit of dirt, most likely, and a whole lot of space. Precisely the stuff you'd find in an empty container garden! Enter NYU graduate student Marco Castro Cosio's Bus Roots, a project which, through installing gardens on the rooftops of New York City buses, seeks to "reclaim forgotten space, increase quality of life and grow the amount of green spaces in the city."

Just how much green space does Cosio hope to reclaim?

"A public transit bus has a surface of 340 square feet. The MTA fleet has around 4,500 buses. If we grew a garden on the roof of every one of the 4,500 buses in the MTA bus fleet, we would have 35 acres of new rolling green space in the city. The equivalent to Four Bryant Parks."